Solid formulations of liquid biologically active agents

ABSTRACT

The instant invention relates to a solid product comprising a liquid biologically active agent which is intimately associated to a stabilizing agent; particularly a solid product that can be reconstituted to a clear, stable, stabilized nanodispersion or loaded micelles comprising a polymer as a stabilizing agent and a liquid, preferably water immiscible, biologically active agent. The instant invention is further directed toward a process for the production of the above solid product; particularly to micelles or nanodispersions produced by hydration of a cake or powder of the solid product, produced via an effective treatment of a stabilized solution comprising for example a polymer as a stabilizing agent, such as an amphiphilic block copolymer or a small molecular weight surfactant, loaded with a liquid biologically active agent, such as propofol, an optional additive, and a suitable solvent.

BACKGROUND OF THE INVENTION

a) Field of the Invention

This invention relates to the preparation of a solid product in the formof a cake, a powder, or the like, by mixing a solvent comprising water,an aqueous solution, at least one non-aqueous organic solvent, orcombinations thereof, with at least one stabilizing agent, andsubsequently adding at least one liquid biologically active agent to theabove mixture; and treating the whole under conditions to give the abovesolid product which is substantially solvent free. More particularly,the invention relates to the above solid product and a method for rapidreconstitution thereof in an aqueous media, whereby an essentiallyclear, lipid free, sterile, stable aqueous product is formed containingnano-dispersions or micelles of the aforementioned stabilizing andbiologically active agents; and to a method of treating a patient inneed of said biologically active agent by administration of said stableaqueous product thereto. In a preferred embodiment, the biologicallyactive agent is water immiscible and may be selected from2,6-bis-(1-methylethyl)phenol or 2,6-diisopropylphenol commonly known aspropofol, 2-phenoxyethanol, quinaldine, methoxyflurane and the like andcombinations thereof. The most preferred biologically active agent ispropofol.

b) Description of the Prior Art

Propofol (known as 2,6-bis-(1-methylethyl)phenol, also known as2,6-diisopropylphenol) is currently the most popular anaesthetic in theworld. It is used for the induction and maintenance of anaesthesia orsedation upon administrations to humans or animals, Intravenousinjection of a therapeutic dose of propofol produces hypnosis rapidlyand with minimal excitation, usually within 40 seconds from the start ofan administration. Fast onset and short half life (10-15 minutes) allowsfor a clinically useful profile with prompt recovery. Due to the risingcost of health care, this quick recovery time is especially advantageousfor increasingly common outpatient procedures.

At room temperature, propofol is an oil that is immiscible with water(aqueous solubility of approximately, 0.154 mg/mL) and is supplied in aemulsion, at concentrations of 1% or 2% (w/w) (2% is used for longersedation). Propofol oil-in-water emulsions currently on the market areDIPRIVAN® (manufactured by AstraZeneca Pharmaceuticals, Inc.,), BAXTER®IPP (manufactured by Gensia Sicor, Inc), and Propofol injectableemulsion (Manuf. Bedford Laboratories).

Extreme care must be taken during manufacture to thoroughly distributethe propofol in the emulsion, as large droplet sizes of propofol in theblood stream have been linked to embolism in humans. These emulsionstypically contain: soybean oil (100 mg/mL), glycerol (22.5 mg/mL) andegg lecithin (12 mg/mL). Emulsions are defined by a large particle size,generally of more than 200 nm, thereby creating a milky white opaqueformulation. This causes visual inspection for foreign particles in theformulation by the anesthesiologist, to be more difficult. The highlipid content of these emulsions has been linked to hyperlipidaemia.

The presence of the egg lecithin and soybean oil in these emulsions alsomakes them highly susceptible to microorganism growth and allergicreactions. In order to suppress bacterial growth, manufacturers haveadded the preservative EDTA (ethylene diamine tetraacetic acid) at 0.05mg/mL to DIPRIVAN® and sodium metabisulfite at 0.25 mg/mL, to BAXTER®PPI propofol, and benzyl alcohol at 1 mg/ml to propofol injectableemulsion of Bedford Laboratories.

Some of these preservatives have been known to cause adverse reactionsin humans. Sodium metabisulfite is a sulfite known to causeallergic-type reactions including anaphylactic symptoms andlife-threatening or asthmatic episodes in certain sulfite sensitiveindividuals. Sodium bisulfite has also been shown to catalyze propofoldegradation. Similarly, the chelating properties of EDTA are of concernto the FDA due to their unfavorable effects on cardiac and renalfunction. Moreover, these emulsions cannot be effectively sterilizedusing standard sterilizing filters, as they are too thermodynamicallyunstable and tend to separate under the shear force required. Suchemulsions are also unstable versus dilution and/or mixing with saline,dextrose or other medication containing solutions. Furthermore, thepresence of egg lecithin as an emulsifier and soybean oil as asolubilizer may produce anaphylactic and anaphylactoid reactions inpersons allergic to eggs and/or soybeans.

Propofol emulsions are known to be thermodynamically unstable, that is,the oil and water components have a tendency to separate when diluted,sheared, cooled, heated, or mixed with other solutions. Furthermore,this separation is accelerated when the formulation is stored at lowtemperatures, i.e. below 2° C., or at elevated temperatures, i.e. above25° C. In addition, these lipid-based emulsions have been associatedwith pain at the injection site, often causing the concomitant use of atopical anaesthetic upon injection.

A variety of methods and procedures have been described in the prior artfor preparing stable formulations for the effective delivery of at leastone hydrophobic compound, particularly pharmaceutical drugs, to adesired location in the body. A number of these methods are based on theuse of auxiliary solvents; surfactants; soluble forms of the drug, e.g.,salts and solvates; chemically modified forms of the drug, e.g.,prodrugs; soluble polymer-drug complexes; special drug carriers such asliposomes; and others.

Indeed, the use of surfactant based micelles has attracted a great dealof interest as a potentially effective drug carrier that is capable ofsolubilizing a hydrophobic drug in an aqueous environment. Typically,micelles and nanodispersions have been shown to alter thepharmacokinetics (and usually the pharmacodynamics) of the biologicalagent to be delivered. Thus, by sequestering the drug within them, theymay prolong the circulation time, may allow more drug to be delivered toa specific location, and/or may allow a different biodistribution whencompared to administration of the drug alone.

However, each of the above procedures is associated with certaindrawbacks, especially when considering the delivery of “on/off” typeanaesthetics, such as propofol. For example, the method based on the useof surfactant micelles to solubilize hydrophobic drugs can be inherentlyproblematic in that some of the surfactants are relatively toxic (e.g.Cremophor EL®) and that precipitation of hydrophobic drugs may occurwhen subjected to dilution. Other methods of preparation yield poorentrapment efficiencies (e.g. equilibration methods), relatively largeparticle sizes (emulsions), or are time-consuming.

Finally, the prolonged circulation time associated with micellar orliposomal delivery can detrimentally affect the “on/off” propertiesrequired of an anaesthetic drug such as propofol

Likewise, there have been studies based on the use of cyclodextrinderivates, which are water-soluble cyclic carbohydrate compounds withhydrophobic interior cavities that complex with propofol allowingdissolution of the drug in water to form a clear solution. However,cyclodextrins are expensive and have been associated with hemodynamicadverse events. Also, long-term stability of cyclodextrin formulationshas been an issue with formulators. More importantly, cyclodextrins havebeen linked with renal toxicity at high doses.

There have also been various attempts investigating the use ofwater-soluble prodrugs comprising a propofol phosphate. However, usuallyprodrugs require much higher doses (up to ten times and more) for thesame response as the instant invention and usually demonstrate a sloweronset of action and slower clearance. Moreover, in some propofolprodrugs one of the bi-products is formaldehyde, a probable carcinogen.Prodrugs are also notably unstable resulting in short shelf lives or lowstorage temperatures to maintain their stability. The beneficialpharmacokinetics are changed due to the use of prodrugs.

Furthermore, when a liquid biologically active agent such as propofol isformulated with the technologies discussed above, a liquid dosage formis produced. However, the stability of such liquid formulations isalways a concern with respect to duration and storage conditions.

Thus, what is lacking in the art is a light-weight, dry powder or cakeformed from a water immiscible liquid drug, such as propofol, that isstable in several different temperature and dilution conditions forprolonged periods, that is readily reconstituted using aqueous media toproduce essentially clear, sterile liquids which do not supportbacterial growth, comprising drug-loaded micelles or nanodispersions inan aqueous medium. The micelles or nanodispersions, which are produceddirectly and spontaneously after addition of the aqueous reconstitutionmedium, allows high loading levels of propofol or other biologicallyactive liquids to be achieved with substantially no effect on stability.

Many studies, literature articles and patents have been directed towardforming stable anaesthetic compositions suitable for parenteraladministration, particularly the administration of propofol and otherdrugs in liquid form.

For example, WO 02/45709 A1 discloses a stable, clear and sterileaqueous composition comprising propofol, a water-soluble emulsifier(TPGS) and water, suitable for parenteral administration and a processfor making the same. However, the final product is a liquid and theprocess of manufacturing requires both the filtration of the compositionthrough a micron-sized filter and autoclaving the sealed containerfilled with the filtrate in order to achieve effective sterilization.

WO 03/030862 A2, discloses inhalation anaesthetic compositions andmethods comprising a suspension of the anaesthetic in an aqueoussolution. The reference teaches the use of surfactant poloxamers, (knownas Pluronics® in the United States and Lutrols® in Europe) toencapsulate the anaesthetic (i.e. propofol) within the micelles. Thepreferred embodiments require the presence of propylene glycol in orderto achieve adequate solubilization of propofol. However, the product issupplied as a liquid and the presence of water in the inhaledanaesthetic is not always beneficial to patients with pulmonarydisorders, such as plural effusion. It will be noted that thecomposition disclosed in this reference is prepared using a mixture ofliquids to constitute a liquid composition.

WO 01/64187 A2 and corresponding U.S. PGPUB No. 2003/0138489 A1, on theother hand, disclose propofol solubilized in aqueous micellarpreparations using combinations of poloxamers to form a clear,injectable solution without inclusion of water-miscible co-solvents,such as propylene glycol. According to WO 01/64187 A2, the use ofwater-miscible co-solvents can have undesirable medical effects, such assuperficial thrombophlebitis, intravasal, haemolytic reactions, andpossible increase in formation of free propofol. Moreover, WO 01/64187A2 indicates that autoclaving may be undesirable when the formulation isfiltered to sterility since autoclaving has been known to disrupt themicelles, to the extent of requiring re-emulsification. In addition,poloxamers are detergent-like surfactants that are not readilydegradable and may open-up tight junctions. Moreover, detergentsurfactants may be a source of pain upon injection and require theaddition of lidocaine to reduce local pain. The final product is aliquid.

U.S. Pat. No. 6,322,805 discloses a biodegradable polymeric drug carriermicelle composition capable of solubilizing a solid hydrophobic drug ina hydrophilic environment. The patent discloses a biodegradablepolymeric drug carrier micelle and a hydrophobic drug wherein the drugis physically trapped within and not covalently bonded to the polymericdrug carrier micelle. The drug carrying micelle is capable of dissolvingin water to form a solution thereof, and the drug carrier comprises anamphiphilic block copolymer having a hydrophilic poly(alkylene oxide)component, and a biodegradable hydrophobic polymer component selectedfrom the group consisting of poly(lactic acid), poly(glycolic acid),poly(lactic-co-glycolic acid), poly(ε-caprolactone), a derivativethereof or a mixture thereof. The disclosed micelle is characterized asa solubilizing agent for a hydrophobic drug. The hydrophobic drug ismixed with the polymeric drug carrier micellar solution and the mixtureis either stirred, heated, subjected to ultrasonic treatment, solventevaporation or dialysis so as to incorporate it into the hydrophobicpolymer core, after which it is formed into an aqueous solution.

U.S. Pat. No. 5,543,158 discloses nanoparticles or microparticles formedof a block copolymer consisting essentially of poly(alkylene glycol) anda biodegradable polymer, poly(lactic acid). In the nanoparticle ormicroparticle, the biodegradable moieties of the copolymer are in thecore of the nanoparticle or microparticle and the poly(alkylene glycol)moieties are on the surface of the nanoparticle or microparticle in anamount effective to decrease uptake of the nanoparticle or microparticleby the reticuloendothelial system. Thus, the nanoparticles ormicroparticles are designed to circulate for prolonged periods withinthe blood fluids. In this patent, the molecular weight of the blockcopolymer is too high to be soluble in water, and a nanoparticle canonly be prepared by first dissolving the block copolymer and a drug inan organic solvent, forming an o/w emulsion by sonication or stirring,and then collecting the precipitated nanoparticles containing the drug.The patent fails to provide the concept of solubilization of hydrophobicdrugs, nor does it teach or suggest the formation of a clear,sterilizable solution containing the polymer/drug blend and subsequentlyophilization thereof, resulting in a readily dispersible micelle ornanodispersion, formed upon reconstitution.

EP 0520888 A1 discloses nanoparticles made of a poly(lactic acid) andpoly(alkylene oxide) block copolymer. A high molecular weightpoly(lactic acid) is used and a surfactant is employed in preparing acolloidal suspension of the nanoparticles. In this patent, nanoparticlesare prepared by dissolving the block copolymer and a drug in an organicsolvent, emulsifying the organic solution in water, and evaporating theorganic solvent to precipitate the nanoparticles containing the drug.The resulting nanoparticles are fine particles having both hydrophilicand hydrophobic components and they cannot form clear stable aqueousliquids.

U.S. Pat. No. 4,997,454 teaches a method for making uniformly sizedparticles from solid compounds for intravenous administration assuspensions of particles of three microns in diameter, or less. Asuitable solid compound is dissolved in a suitable solvent, and aprecipitating liquid is infused to form non-aggregated particles whichare separated from the liquid mixture. The product is a liquidcomprising a suspension of solid microspheres.

U.S. Pat. Nos. 4,370,349 and 4,311,712 disclose a process for preparinga freeze-dried, liposomal, mixture which comprises either (a) dissolvingat least one liposome-forming amphiphilic lipid, at least onebiologically-active compound, and optionally one or more adjuvants, in asuitable solvent, and then freeze-drying the solution, or (b) preparingby any known method an aqueous liposome composition containing at leastone biologically-active compound, and then freeze-drying the saidaqueous liposome composition. The patents are particularly directedtoward a process for preparing an aqueous liposome composition whichcomprises dispersing said freeze-dried, potential liposomal, mixture,obtained by procedure (a) or (b), in a suitable aqueous medium. Theprocess of the instant invention is not directed toward liposomeproduction.

U.S. Pat. No. 6,780,324 teaches a unique process wherein a solution isformed from a hydrophobic biologically active agent, in combination witha dispersing agent and a suitable solvent or solvent blend (which mayfurther include water), the mixture being lyophilized and thereafterrehydrated to form a biologically active agent loaded micelle ornanodispersion. The instant invention provides an improved method forforming a biologically active agent loaded micelle or nanodispersionfrom a liquid hydrophobic biologically active agent by first forming asolution of a stabilizing agent and solvent (which solvent may solelycomprise water), to which is added a liquid hydrophobic biologicallyactive agent. This is followed by lyophilization and/or any treatmentthat will result in a solid product that is substantially free ofsolvent.

U.S. Pat. No. 6,835,396 discloses the preparation of submicron sizedparticles by mixing a pharmacologically active compound with a waterimmiscible solvent to form an organic phase. On the other hand there isprovided an aqueous phase containing a surface active compound. Theorganic phase and the aqueous phase are combined to form a crudedispersion and the latter is treated with a sonication device allowingcavitation to occur. The dispersion is then frozen and lyophilized toprovide particles having a mean particle size of less than 500 nm.

Ideally therefore, propofol should be available as a solid product thatcan instantaneously be hydrated to form a clear stable solution readyfor injection. For this purpose, a test was made by lyophilizing amixture of water and propofol. The result is that water and propofol hadall evaporated and nothing remained. This is an indication that otheravenues must be investigated.

Accordingly, it is a main objective of the instant invention to providea process for the formation of a sterile, solid loaded micelle ornanodispersion comprising a liquid biologically active agent in anamphiphilic biodegradable polymer.

An additional objective of the invention is to produce a stable cake orpowder that is readily reconstituted to form an essentially clearaqueous liquid containing a stabilized drug nanodispersion or loadedmicelle.

It is still a further objective of the instant invention to provide aprocess whereby a clear liquid comprising a biologically active agent,polymer and optionally an additive (e.g. a bulk forming agent, acryoprotectant, a lyoprotectant) and/or stabilizer is formed using anysuitable solvent prior to a treatment such as freeze-drying, spraydrying, and the like.

Another objective of the present invention is to provide a storablepowder that is instantaneously reconstituted before administration to apatient for long-term infusions as well as bolus (highly concentrated)injections.

Another objective of the present invention is to provide micelles ornanodispersions loaded with liquid biologically active agents thatrelease quickly into body fluids and tissues post administration.

Yet another objective of the instant invention is the formation of apowder that yields a longer shelf life and lighter product.

It is still a further objective of the invention to provide a sterileformulation without the need for preservatives.

Another objective of the invention is to provide a formulation thatreduces or eliminates any sensation of pain upon administrationcommonly, which has been associated with currently marketedformulations.

It is a further objective of the instant invention to provide, oncereconstituted, a liquid medical formulation that is stable for more than24 hours at high drug loading levels at room temperatures.

Another objective of the present invention is to provide a formulationthat is stable after dilution, when subjected to shear forces, or whenmixed with saline, dextrose or other medication containing solutions(e.g. injectable lidocaine solutions).

Another objective of the present invention is to provide a solidformulation that, upon reconstitution, does not support bacterialgrowth.

Another objective of the present invention is to provide a formulationthat is lipid free.

DEFINITIONS

The term “stabilizing agent” as used in the present specification andclaims, is intended to mean a vehicle or material which allows aqueouspreparations of water insoluble drugs.

The term “essentially clear” as used in the present specification andclaims, is intended to mean a stable solution of a reconstitutionsolvent and a reconstituted solid, wherein a solid product comprising anintimate mixture of at least one stabilizing agent and at least oneliquid biologically active agent loaded within the stabilizing agent,upon reconstitution, forms a clear stable reconstituted solution inwhich said at least one biologically active agent is present asstabilized nanodispersions or loaded micelles up to about 13% drugloading level, an increasingly opalescent solution at about 13% to about20% drug loading level, and a transparent, cloudy suspension at greaterthan about 20% drug loading level. Nevertheless, all of theseformulations of the instant invention are stable for more than 24 hours,i.e. they do not precipitate upon dilution in water and/or albumin 35g/L solution. PPF-PM means propofol-polymeric micelle

SUMMARY OF THE INVENTION

In order to overcome the problems encountered by the prior art, theinstantly disclosed invention relies on a treatment, such aslyophilization, spray drying, or the like well known to those skilled inthe art, which is obtained by mixing a solvent selected from water, anaqueous solution, at least one non-aqueous organic solvent, orcombinations thereof with at least one stabilizing agent underconditions to provide a first solution, to which is subsequently addedat least one liquid biologically active agent such as propofol or thelike, to give a second solution. The latter is lyophilized, spray-dried,or the like under conditions which yield a solid product, in which theliquid biologically active agent is intimately associated, and fromwhich substantially all the solvent or solvents have been removed andwhere virtually no loss of drug occurs during the treatment; optionallyan additive, non-limiting examples of which include a buffer, a bulkforming additive, a cryoprotectant, and a lyoprotectant may be added atany stage during the treatment.

Such a liquid can be subjected to a sterilizing filtration step prior tothe above treatment to form a powder, a cake or the like. The solidproduct resulting from the above treatment is a light-weight, lipid freematerial that can be stored, transported and then reconstituted prior touse by the addition of an aqueous solution e.g. water, saline, dextroseor the like to form essentially clear, stable, sterile, liquidscomprising nanodispersions or micelles in aqueous medium.

The instant process illustrates a simple and elegant procedure forforming a solid product from a liquid containing an intimate associationof an insoluble liquid drug and a stabilizing agent. The liquid,comprising an intimate association of the solvent, insoluble liquid drugand stabilizing agent, may be dried by a process, whereby the insolubleliquid drug remains in close association with the stabilizing agent suchthat virtually all drug is retained during the process. The product is adry, solid as mentioned above. The dry solid product upon addition ofwater or an aqueous solution spontaneously reconstitutes to form anessentially clear stable liquid comprising drug micelle or drugnanodispersions loaded with a liquid biologically active agent.

Broadly, the invention relates to a solid product suitable forreconstitution to a clear, stable solution upon addition of an aqueoussolvent thereto, the solid product comprising an intimate mixture of atleast one stabilizing agent, and at least one liquid biologically activeagent, non-limiting examples of which are propofol, 2-phenoxyethanol,quinaldine, methoxyflurane, and the like, loaded within the stabilizingagent, in such a manner that the liquid biologically active agent isintimately associated with the stabilizing agent in a substantiallysolid product. The substantially solid product upon rehydration with areconstituting aqueous solvent or solution, is capable of forming theessentially clear stable solution in which at least one biologicallyactive agent is present as nanodispersions or micelles loaded with theat least one biologically active agent.

The invention also relates to a process for the production of a solidproduct suitable for reconstitution to a clear stable solution uponaddition of an aqueous solution thereto, which is produced by forming afirst mixture comprising a solution of at least one stabilizing agent,and at least one solvent, under conditions to achieve micelle ornanodispersion formation, subsequently adding at least one liquidbiologically active agent, such as propofol, 2-phenoxyethanol,quinaldine, methoxyflurane, and the like, to the first mixture in such amanner to load the micelle or nanodispersion therewith and form a secondmixture, and treating the second mixture under conditions effective toremove the solvent therefrom while forming a substantially solid productthat contains the liquid biologically active agent intimately associatedwith the stabilizing agent, the solid product upon rehydration beingcapable of forming an essentially clear stable solution in which the atleast one biologically active agent is present as a nonodispersion ormicelle loaded with the at least one biologically active agent.

The invention also comprises a process for the production of astabilized nanodispersion or loaded micelle containing a liquidbiologically active agent by hydrating the above solid product underconditions to provide a stabilized nanodispersion or loaded micellecontaining the liquid biologically active agent.

The invention also comprises the essentially clear liquid productobtained by reconstituting the solid product defined above, and a methodof medical treatment which comprises administering to a patient theabove essentially clear liquid comprising a stabilized nanodispersion orloaded micelle of the liquid biologically active agent.

The invention additionally comprises a device for producing solidformulations of liquid biologically active agents comprising

-   -   a container,    -   means for adding at leas one stabilizing agent and at least one        solvent into the container,    -   mixing means operable with the container to form a first mixture        of the stabilizing agent and the solvent under conditions to        achieve micelle or nanodispersion therein,    -   means for subsequently adding a liquid biologically active agent        to the first mixture and to form a second mixture,    -   means operating the mixing means under conditions to treat the        second mixture to load the micelle or nanodispersion with the        biologically active agent, and    -   means for treating the loaded micelle or nanodispersion to form        a solid product containing the liquid biologically active agent        intimately associated with the stabilizing agent and        substantially free of the solvent.

Examples of suitable stabilizing agents include, but are not limited toamphiphilic polymers such as linear, branched or star-shaped blockamphiphilic copolymers where the hydrophilic part may include at leastone member selected from a group consisting of poly(ethylene oxide),poly(N-vinylpyrrolidone), poly(N-2-hydroxypropyl methacrylamide),poly(2-ethyl-2-oxazoline), poly(glycidol),poly(2-hydroxyethylmethacrylate), poly(vinylalcohol), polymethacrylicacid derivatives, poly(vinylpyridinium),poly((ammoniumalkyl)methacrylate), poly((aminoalkyl)methacrylate) andcombinations and derivatives thereof; and wherein the hydrophobicsegment may include at least one member which is selected from a groupconsisting of a poly(ester), poly(ortho ester), poly(amide),poly(ester-amide), poly(anhydride), poly(propylene oxide),poly(tetrahydrofuran) and combinations thereof.

The poly(ester) may be at least one member selected from a groupconsisting of poly(e-caprolactone), poly(lactide), poly(glycolide),poly(lactide-co-glycolide), poly(hydroxy alkanoates) (e.g. poly(γ-hydroxybutyrate)), poly(δ-hydroxy valerate)), poly (β-malic acid),and derivatives thereof.

Other non-limiting illustrative examples of stabilizing agents mayinclude at least one member selected from the group consisting of sodiumlauryl sulfate, hexadecyl pyridinium chloride, polysorbates, sorbitans,poly(oxy ethylene) alkyl ethers, polyoxyethylene) alkyl esters and thelike, including various combinations thereof.

Without limiting the scope of the present invention, suitable agents forincorporation into the nanodispersion or micelles produced in accordancewith the teachings of the instant invention may include at least oneanaesthetic agent, such as propofol, at a physiologically effectiveamount, preferably provided at a concentration of about 0.1% to 15%,preferably 1% to 10% (w/v), of propofol. Typically personalcharacteristics, including but not limited to age, weight and/or healthdictate the physiologically effective amount, or dosage, necessary.

Suitable solvents or mixtures thereof will have the ability to solublizeappropriate amounts of the stabilizing agent as well as appropriateamounts of liquid biological agent without denaturation or degradationof the liquid biological agent. Preferred solvents (or mixtures ofsolvents) should be removed during the lyophilization, spray-drying orthe like process. While numerous solvents are capable of functioning inaccordance with the process of the instant invention, non-limitingillustrative examples of such solvents include water, dextrose solutionin water, saline, DMSO, DMF, dioxane, pyridine, pyrimidine, andpiperidine, alcohols such as methanol, ethanol, n-butanol and t-butanol,and acetone, which are useful either alone or in combination, and may befurther admixed, e.g. with water, to form a binary mixture. Othersolvents may be added in small amounts to facilitate the dissolution ofthe drug.

Objectives and advantages of this invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings wherein are set forth, by way of illustration and examples,certain embodiments of this invention. The drawings constitute a part ofthis specification and include exemplary embodiments of the presentinvention and illustrate various objectives and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical representation of pharmacodynamic effects obtainedin vivo 001 (example 3) of Diprivan® versus three propofol polymericmicelle formulations after iv administration at 10 mg/kg in femaleSprague-Dawley rats.

FIG. 2 is a graph showing the comparison of the time for righting reflexin pharmacodynamic study #1 (example 3) and #2 (example 9).

FIG. 3 is a graph showing the mean concentration-time profiles ofpropofol in blood following the intravenous administration of Diprivan®and three PPF-PM formulations (10 mg/kg).

FIG. 4 is a graph showing the mean concentration-time profiles ofpropofol in plasma following the intravenous administration of Diprivan®and three PPF-PM formulations.

FIG. 5 is a graph showing the mean (±SD) withdrawal reflex time, time offirst movement and time of righting following the intravenousadministration of Diprivan® (1), PPF-PM 7%, PPF-PM 10% and PPF-PM 12% inmale Sprague-Dawley rats obtained in vivo 003 study (example 10).

FIG. 6 is a graph showing the mean (±SD) pay withdrawal reflex timefollowing the intravenous administration of Diprivan (1), PPF-PM 7% (2),PPF-PM 10% (3) and PPF-PM 12% (4) in male Sprague-Dawley rats obtainedin vivo 003 study (example 10).

FIG. 7 is a graph showing Staphylococcus Aureus growth in water, inpolymer solution in water, propofol polymeric micelle (PPF-PM) solutionin water for injection and Diprivan®.

FIG. 8 is a graph showing Staphylococcus Aureus growth in dextrose, inpolymer solution in dextrose (PVP-PLA), propofol polymeric micelle(PPF-PM) solution in dextrose and Diprivan®.

FIG. 9 is a graph showing Staphylococcus Aureus growth in saline, inpolymer solution in saline (PVP-PLA), propofol polymeric micelle(PPF-PM) solution in saline and Diprivan®.

FIG. 10 is a graph showing E, Coli growth in water, in polymer solutionin water (PVP-PLA), propofol polymeric micelle (PPF-PM) solution inwater and Diprivan®.

FIG. 11 is a graph showing E. Coli growth in dextrose, in polymersolution in dextrose (PVP-PLA), propofol polymeric micelle (PPF-PM)solution in dextrose and Diprivan®.

FIG. 12 is a graph showing E. Coli growth in saline, in polymer solutionin saline (PVP-PLA), propofol polymeric micelle (PPF-PM) solution insaline and Diprivan®.

FIG. 13 is a graph showing Pseudomonas Aeruginosa growth in water, inpolymer solution in water (PVP-PLA), propofol polymeric micelle (PPF-PM)solution in water and Diprivan®.

FIG. 14 is a graph showing Pseudomonas Aeruginosa growth in dextrose, inpolymer solution in dextrose (PVP-PLA), propofol polymeric micelle(PPF-PM) solution in dextrose and Diprivan®

FIG. 15 is a graph showing Pseudomonas Aeruginosa growth in saline, inpolymer solution in saline (PVP-PLA), propofol polymeric micelle(PPF-PM) solution in saline and Diprivan®.

FIG. 16 is a graph showing Candida Albicans growth in water, in polymersolution in water (PVP-PLA), propofol polymeric micelle (PPF-PM)solution in water and Diprivan®.

FIG. 17 is a graph showing Candida Albicans growth in dextrose, inpolymer solution in dextrose (PVP-PLA), propofol polymeric micelle(PPF-PM) solution in dextrose and Diprivan®.

FIG. 18 is a graph showing Candida Albicans growth in saline, in polymersolution in saline (PVP-PLA), propofol polymeric micelle (PPF-PM)solution in saline and Diprivian®.

FIGS. 19 A-C illustrate colony counts after 24-hour incubation time ofall strains and all reconstitution media, polymer solutions andformulations.

FIG. 20 is a schematic representation of a drug loading procedure andpreparation of an essentially clear solution thereof according to theinvention.

FIG. 21 is a schematic illustration of a device for producing a soliddrug formulation according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

In accordance with the schematic representation set forth in FIG. 20,predetermined amounts of a stabilizing agent, e.g. a suitable polymer,copolymer or a surfactant or a dispersing agent, and optionally, anadditive, e.g. a buffer, a cryoprotectant/a lyoprotectant/a bulk formingagent or the like (e.g. commercially available poly (vinylpyrrolidone)Kollidon 12 PF® or 17 PF®, BASF) and/or additional stabilizing agentsare dissolved in a solvent, e.g. water, an aqueous solution, at leastone non-aqueous organic solvent, or combinations of water or an aqueoussolution and said at least one non-aqueous organic solvent to form afirst mixture in the form of a micellar solution. It has been realizedthat proper mixing achieves micelle or nanodispersion formation withinthe first mixture.

Once the first mixture is well formed, a liquid drug, here propofol,although any other liquid biologically active agent may be used as willbe appreciated by one skilled in the art, is added to the first mixtureunder conditions well known to those skilled in the art, whereby themicelle or nanodispersion will be loaded with the liquid drug in asecond mixture in the form of a drug micellar clear solution.

In either or both of the mixing steps described above, a suitable“additive” could be added for purposes well known to those skilled inthe art. Non limiting examples of additives include, but are not limitedto buffers, cryoprotectants, lyoprotectants, analgesics and bulk formingagents. Other suitable additives include, but are not limited topoly(vinylpyrrolidone), poly(ethylene glycol), sugars (lactose,trehalose), polyols (mannitol), saccharides and amino acids soluble inthe solvent or solvent mixture. As broadly recited herein, the term“solvent” is understood to mean water alone, water with at least onenon-aqueous organic solvent, or combinations of water and said at leastone non-aqueous organic solvent. In one illustrative embodiment,additional dissolution enhancing means, here stirring, may be employedto aid in the forming of the liquid comprising a biologically activeagent, a stabilizing agent and a solvent, prior to treatment to form asolid product. Illustrative, but non-limiting examples of saiddissolution enhancing means may include a process, for example, whereinthe mixture may be stirred, vortexed and sonicated, if needed. For somepolymers, the solution may also need to be heated to speed updissolution.

In the illustrated embodiment, the solution is filtered through asterilizing filter, e.g. through a 0.2 μm filter. Subsequently, thesolution is freeze-dried to form a sterile dry cake or powder or thelike.

Lastly, for administration to a patient, the dried powder or cake isreconstituted with water, saline 0.9%, dextrose 5%, or other suitablesolvent, or drug containing aqueous solutions, whereby a stablenanodispersion or loaded micelle is spontaneously produced.

The reconstituted formulation comprising nanodispersions or micelles ina suitable (usually aqueous) solvent may be characterized by;

-   -   1. Particle size and particle size distribution of the        nanodispersion or micelle e.g. as determined by dynamic light        scattering;    -   2. Clarity of the liquid e.g. as determined by degree of light        transmittance at 660 nm;    -   3—pH;    -   4—Drug content/dose/concentration;    -   5—Viscosity (not in examples though);    -   6—Osmolality

In the present invention, the drug loading levels of 1 to 10% w/w werefound to produce clear/stable solutions at any volume of reconstitutionfrom 10 mg/mL, (found in commercially available propofol emulsions), to100 mg/mL. However, at the latter concentration, the solution'sviscosity becomes an issue for injection. Hence, the concentration ofpolymer in water is the limiting factor for reconstitution volume offormulations.

Starting at around 12% drug loading level, reconstituted solutions,while remaining essentially clear, become increasingly opalescent, witha blue tint at 12% to a transparent, cloudy suspension at 20% and more.Nevertheless, all of these formulations of the instant invention werefound to be stable for more than 24 hours, i.e. they do not precipitateupon dilution in water and/or albumin 35 g/L solutions. The opalescencesuggests the swelling of the micelles to bigger sizes causing lightdiffraction observable by the naked eye.

The presence of albumin does not affect the stability of the propofolformulation of the current invention. Dilutions of 10, 20, and 40 mg/mLformulations at 5% w/w, 7% w/w, 10% w/w, and 15% w/w drug loading levelsin 35 g/L albumin solutions showed no significant turbidity ordifferences with reconstituted solutions in water, saline or dextrose.That is, the clear solutions stayed clear, with no visible precipitationof polymer and/or albumin and/or floating propofol (phase separation isnot present). Similarly, the opalescent suspensions stayed opalescent,but less so after dilution, with no precipitation of polymer and/oralbumin and/or floating propofol.

With reference to FIG. 21, a device for carrying out the preparation ofa solid product according to the invention comprises a container 1 whichis connected in known manner to a supply 3 of solvent, here water, and asupply 5 of a stabilizing agent, here PVP-PDLLA. A mixer 7 is providedin container 1 to stir the mixture of water and PVP-PDLLA underconditions for forming a micelle or nanodispersion.

A supply 9 of propofol is also connected in known manner to container 1to add propofol thereto once micelle or nanodispersion is achievedthrough stirrer 7 thereby forming a second mixture comprising a micelleor nanodispersion loaded with propofol.

In the non limiting illustrated embodiment, there is provided a filter11 allowing for sterilization of the micelle or nanodispersion, filter11 being connected in known manner to container 1 through duct 13. Vials15 are provided at 15 downstream of filter 11, to receive filteredquantities of sterilized micelle or nanodispersion. Vials 15 areconnected in known manner through duct 17 to filter 11.

The device also comprises a lyophilizer 19 of known constructionconnected in known manner to vials 15 through duct 21 downstream ofvials 15. A recipient 23 is finally connected to vials 15 through duct25 to collect the solid product 27 obtained through lyophilization.

EXAMPLES

The invention will now be illustrated but is not limited by means of thefollowing examples. The stabilizing agents used are different types ofcommercially available poly(N-vinylpyrrolidone)-b-poly(d,l-lactide)copolymers, while the liquid biologically active agent is propofol. Itis understood that other stabilizing agents and liquid biologicallyactive agents could also be used with similar results as will beappreciated by one skilled in the art.

Characteristics of PVP-PDLLA lots used in the following examples aregiven in Table 1.

TABLE 1 Characteristics of PVP-PDLLA lots used in the following examplesPDLLA PDLLA PVP-PDLLA Wt %¹ mol %¹ Mw² Mn² PDI POLYMER 1 36.7 47.2 39003500 1.1 POLYMER 2 38.1 48.8 4500 3900 1.2 POLYMER 3 35.7 46.4 4961 41771.2 POLYMER 4 36.7 47.2 4591 4012 1.1 POLYMER 5 33.6 43.8 4685 3872 1.2¹Weight and molar percentages were measured from elemental analysis ofpolymer samples. ²Absolute molecular weights were determined using a GelPermeation Chromatography system equipped with a light scatteringdetector.

Example 1

PVP-PDLLA (POLYMER 1 and POLYMER 2) samples were dissolved in mixturesof water and various amounts of tert-butyl alcohol (TBA). Propofol isthen added to the PVP-PDLLA solution. Water is then added to theTBA/PVP-PDLLA/propofol solution to the desired final volume. Final TBAconcentration in these solutions was 10-30%. Drug loading levels, % w/wof propofol/(propofol PVP-PDLLA), were also varied from 5, 7, 8, 10, 12,15 and 20%. Solutions were then frozen in a dry ice/acetone bath andlyophilized for at least 24 hours. Lyophilized cakes obtained were thenreconstituted by adding water to obtain an aqueous solution of propofol1% w/v in less than 30 seconds. Overall results indicated that at 10%w/w drug loading levels and below, solutions were 100% homogenous. Atdrug loading levels above 10% w/w, the solutions were gradually more andmore opalescent (bluish tint caused by diffracted light). At 20%,solutions are cloudy, but stable (no precipitation for more than 8hours).

Example 2

PVP-PDLLA (POLYMER 1) is dissolved directly in water at concentrationsbetween 100 to 350 mg/mL. Propofol is added to the PVP-PDLLA solutionand mixed until a homogenous solution is obtained. The solution is thendiluted to a concentration of 1% w/v of propofol. 7, 10 and 12% w/w drugloading levels were tested. All solutions were then filtered using 0.2μm sterile filters and frozen in acetone/dry ice bath or in −80° C.freezer for at least 4 hours before being lyophilized for 48 hours.Solid lyophilized cakes of 7, 10 and 12% w/w were reconstituted byadding water for injection. 7 and 10% w/w drug loading levels yieldhomogenous solutions, while the 12% w/w yielded a slightly opalescentsolution (bluish tint). All where stable for more than 8 hours, i.e. noprecipitation or phase separation under visual observation.

TABLE 2 Reconstituted formulation characteristics of example 1. SampleID DLL theo DLL exp Osmolality Particle size¹ FR041124 (% w/w) (%) mOsm(nm) POLYMER 1 7 6.7 438 23 (99%)* POLYMER 1 10 9.6 355 26 (99%)*POLYMER 1 12 11.4 342 20 (99%)* *size of main peak (intensity signal)and volume percentage occupied by the main peak. All were reconstitutedin 5% Dextrose

Example 3

Formulations found in table 2 were tested in female Sprague-Dawley ratsat a dose of 10 mg/kg. Injection time was 1 minute. All formulationsprepared had a propofol concentration of 1% w/v, i.e. 10 mg/mL.

TABLE 3 Pharmacodynamic parameters of Diprivan versus three propofolpolymeric micelle formulations in Sprague-Dawley rats. Time of Time ofTime of First Righting Full Onset Movement Reflex Recovery Formulationof (min ± (min ± (min ± (n = 5) % DLL Sleep Std Dev) Std Dev) Std Dev)Diprivan ® ca. 7% <1 min  8 ± 3.4 10.4 ± 2.7 19.2 ± 3.3 FR041124-11  7%<1 min 8.7 ± 1.5  9.3 ± 1.5 17.7 ± 0.6 FR041124-21 10% <1 min 10.2 ± 2  10.4 ± 2.1 17.4 ± 2.7 FR041124-31 12% <1 min 9.8 ± 3.0 11.2 ± 1.9 18.2 ±1.1The results of the above study are illustrated in FIG. 1 which is asleep/recovery study upon iv administration of 10 mg/kl of propofolformulation in rats (onset of sleep less than 1 min).

Example 4

PVP-PDLLA (POLYMER 2) is dissolved in water at concentrations between100 to 350 mg/mL. Propofol is added to the PVP-PDLLA solution and mixeduntil a homogenous solution is obtained. The solution is then diluted toa concentration of 1% w/v of propofol. 7, 10 and 12% w/w drug loadinglevels were tested. All solutions were then filtered using 0.2 μmsterile filters and frozen in acetone/dry ice bath before beinglyophilized for 48 hours. Solid lyophilized cakes of 7, 10 and 12% w/wwere reconstituted by adding water. 7 and 10% w/w drug loading levelsyielded homogenous solutions, while the 12% w/w yielded a slightlyopalescent solution (feeble blue tint). All where stable for more than 8hours, i.e. no precipitation or phase separation under visualobservation.

Example 5

PVP-PDLLA (lot # POLYMER 3) is dissolved in water at concentrationsbetween 100 to 350 mg/mL. Propofol is added to the PVP-PDLLA solutionand mixed until a homogenous solution is obtained. The solution is thendiluted to a concentration of 1% w/v of propofol. 7, 10 and 12% w/w drugloading levels were tested. All solutions were then filtered using 0.2μm sterile filters and frozen in acetone/dry ice bath before beinglyophilized for 48 hours. Solid lyophilized cakes of 7, 10 and 12% w/wwere reconstituted by adding water. 7 and 10% w/w drug loading levelsyielded homogenous solutions, while the 12% w/w yielded a slightlyopalescent solution (feeble blue tint). All were stable for more than 8hours, i.e. no precipitation or phase separation under visualobservation.

Example 6

PVP-PDLLA (lot # POLYMER 2) is dissolved in sodium phosphate buffer pH7.4. Propofol is added to the PVP-PDLLA solution and mixed until ahomogenous solution is obtained. 10% drug loading level is tested. Wateris then added to obtain a 1% w/v propofol concentration and a sodiumphosphate buffer concentration ranging from 10 to 100 mM. Osmolality, pHand particle size of reconstituted solutions were obtained (table 4).

TABLE 4 pH, Osmolality and particle size as a function of sodiumphosphate buffer concentration and time. Phosphate Time after bufferconc. reconstitution Osmolality Particle size (mM) hours pH (mOsm) (nm)ca. 100 0 7.4 356 41 ca. 24 7.1 369 36 75 0 7.3 323 35 ca. 24 7.1 336 3250 0 7.2 232 32 ca. 24 6.9 241 30 10 0 6.5 105 29 ca. 24 5.9 110 30

Example 7

PVP-PDLLA (lot # POLYMER 1, POLYMER 2, POLYMER 3, POLYMER 4 and POLYMER5) is dissolved directly in 100 mM sodium phosphate buffer, pH 7.4, atconcentrations between 100 to 350 mg/mL. Propofol is added to thePVP-PDLLA solution and mixed until a homogenous solution is obtained.The solution is then diluted to a concentration of 1% w/v of propofoland 70 mM of sodium phosphate buffer concentration. 7, 0.10 and 12% w/wdrug loading levels were tested. All solutions were then filtered using0.2 μm sterile filters and frozen in acetone/dry ice bath or in −80° C.freezer for at least 4 hours before being lyophilized for 48 hours.Solid lyophilized cakes of 7, 10 and 12% w/w were reconstituted byadding water for injection. 7 and 10% w/w drug loading levels yieldhomogenous solutions, while the 12% w/w yielded a slightly opalescentsolution (bluish tint). All reconstituted solutions were stable for morethan 24 hours, i.e. no precipitation or phase separation under visualobservation. Characteristics of samples can be found in tables 5, 6 and7.

TABLE 5 Formulation characteristics for lot # POLYMER 3 at 70 mM sodiumphosphate buffer concentration Propofol DLL (%) Osmolarity Particlesize¹ Conc² % T + w/w pH mOsm (nm) (mg/mL) (660 nm) POLYMER 3 7 6.96 37042 (100%)  10.1 99.0 POLYMER 3 10 7.05 292 39 (99.9%) 9.9 98.6 POLYMER 312 7.1 283 50 (99.3%) 9.8 97.5

TABLE 6 Formulation characteristics for POLYMER 4 at 70 mM sodiumphosphate buffer concentration DLL Particle Propofol Water Sample ID (%)Osmolarity size¹ Conc² % T content³ MT050816 w/w pH mOsm (nm) (mg/mL)(660 nm) (% w/w) POLYMER 4 7 6.85 282 26.9 (100%) 10.1 99.6 0.7 POLYMER4 10 6.94 243 26.1 (100%) 10.2 98.9 0.9 POLYMER 4 12 7.0 226 27.4 (100%)10.0 99.1 0.9

TABLE 7 Formulation characteristics for POLYMER 5 at 70 mM sodiumphosphate buffer concentration DLL Particle Propofol Water Sample ID (%)Osmolarity size¹ Conc² % T content³ MT050809 w/w pH mOsm (nm) (mg/mL)(660 nm) (% w/w) POLYMER 5 7 6.83 292 28.1 (100%)  9.8 98.7 0.6 POLYMER5 10 6.93 248 29.5 (99.8%) 9.4 98.8 0.8 POLYMER 5 12 6.96 230 30.0(99.0%) 8.7 96.6 0.9¹ Particle size measured using Malvern zeta sizer. Size is selected fromthe main peak of the intensity signal. Percentages in brackets representthe volume fraction of micelles of that main peak.²Propofolconcentration is determined by HPLC method.³Water content is determined by Karl Fisher titration.

Example 8

PVP-PDLLA (POLYMER 4) is dissolved directly in 100 mM sodium phosphatebuffer, pH 7.4, at concentrations between 140 to 300 mg/mL, depending ondrug loading level. One of the two 10% w/w drug loading levelformulations was dissolved in water. Propofol is added to the PVP-PDLLAsolutions and mixed until homogenous solutions are obtained. Thesolutions are then diluted to a concentration of 1% w/v of propofol and70 mM of sodium phosphate buffer concentration. 7, 10 and 12% w/w drugloading levels were tested. All solutions were then filtered using 0.2μm sterile filters and frozen in −80° C. freezer for at least 4 hoursbefore being lyophilized for 48 hours. Solid lyophilized cakes of 7, 10and 12% w/w were reconstituted by adding water for injection, except forone formulation containing no phosphate buffer that was reconstituted in5% dextrose w/w. All reconstituted solutions were stable for more than24 hours, i.e. no precipitation or phase separation under visualobservation.

Example 9

In-vivo 002. Using propofol-PM formulations presented in Example 8, andDiprivan® (commercial propofol 1% w/v formulation), a pharmacodynamicstudy was performed. The objectives of this study were:

-   -   1. Evaluate the pharmacodynamic effect of changing PVP-PDLLA        molecular weight in the formulation    -   2. Evaluate the changes in pharmacodynamic parameters when using        a sodium phosphate buffer to control pH and Osmolality    -   3. Compare results

Lyophilized solid formulations of propofol-PM were reconstituted to ahomogenous solution by adding water for injection (WFI) or dextrose 5%w/v for injection (sample MT050816-3). Final propofol concentration insolutions is 1%, equivalent to the commercial formulation Diprivan®.Female Sprague Dawley rats were injected a bolus dose of 10 mg/kg in 60seconds. Pharmacodynamic parameters were then measured. Tables 8 and 9present selected characteristics and parameters of interest.

For a comparison of a time for righting reflex measured in in vivo 002and in vivo 001 sleep/recovery study, reference is made to FIG. 2.

TABLE 8 In-house propofol-PM formulation compositions to be tested insecond pharmacodynamic study. Final concentration Reconstitutionpropofol Polymer % w/w of Phosphate % T conc. Lot# batch# DLL* Buffer(mM) Medium Speed (660 nm) (mg/mL) MT050816-1 POLYMER  7% 70 WFI <1 min99.6 10.2 4 MT050816-2 POLYMER 10% 70 WFI <1 min 98.9 10.46 4 MT050816-3POLYMER 10% 0 Dextrose <1 min 98.9 9.9 4 5% MT050817-4 POLYMER 12% 70WFI <1 min 99.3 10.26 4 *All parts percentages of drug loading reportedherein are weight per unit weight (w/w), in which the weight in thedenominator represents the total weight of the formulation (polymer anddrug, excluding buffering excipients).

TABLE 9 In-house propofol-PM formulation compositions to be tested insecond pharmacodynamic study: Characteristics and results RESULTS Timeof Micelle size* Righting Formulation % DLL (nm) Osmolality % T Onset ofReflex (min ± (n = 5) w/w (Volume %) pH mOsmol (660 nm) Sleep Std Dev)Diprivan ® Ca. 7% ND 7 311 ND <1 min 10.4 ± 3.3 MT050816-1  7% 30.3(100) 6.86 284 99.6 <1 min 11.6 ± 1.7 MT050816-2 10% 31.5 (100) 6.95 24098.9 <1 min 10.4 ± 2.9 MT050816-3 10%  37.6 (99.5) 3.32 315 98.9 <1 min10.4 ± 1.7 (no PB) MT050817-4 12%  32.8 (99.95) 7.02 224 99.1 <1 min10.3 ± 1.3 *Particle size measured using Malvern zeta sizer. Size isselected from the main peak of the intensity signal. Percentages inbrackets represent the volume fraction of micelles of that main peak.

Example 10

In-vivo 003. Using formulations prepared according to the protocol inexample 8, pharmacokinetic and pharmacodynamic studies were performed inMale Sprague-Dawley rats. Formulations tested and pharmacokinetic studydesign, which included Diprivan, are presented in the table below.

TABLE 10 Pharmacokinetic groups and details Dose Injection Number Dosevolume time of Group Formulation (mg/kg) (mL/kg) (sec) Animals Matrix 1Diprivan ® 10 1 30 5 Blood 2 5 Plasma 3 Propofol-PM 10 1 30 5 Blood 4(7% w/w) 5 Plasma 5 Propofol-PM 10 1 30 5 Blood 6 (10% w/w) 5 Plasma 7Propofol-PM 10 1 30 5 Blood 8 (12% w/w) 5 Plasma

Forty male Sprague-Dawley Rats (300-325 g) were used to determine thepharmacokinetic properties The animals were equally allotted into fourgroups (n=5) A, B, C and D corresponding to the four treatmentsDiprivan®, Propofol-PM 7%, 10% and 12% (w/w).

TABLE 11 Summary of mean pharmacokinetic parameters for propofol inblood for Diprivan ® and PPF-PM formulations PK PPF-PM PPF-PM PPF-PMparameters Units Diprivan ® 7% w/w 10% w/w 12% w/w C_(max) μg/mL 18.65 14.4 * 19.1 19.0 C₀ μg/mL 20.4 14.1 21.7 18.5 AUC t μg · min/mL 262.3246.6  255.6 258.1 AUC inf μg · min/mL 301.1 271.5  272.8 282.9 CLmL/min/kg 31.3 28.4 22.5 25.4 MRT Min 34.1 39.6 37.1 36.6 T ½ Min 28.622.5 20.0 22.9 T ½ {acute over (α)} Min 3.1  2.6 2.9 3.0 T ½ β Min 40.924.7 37.8 26.0 λ₁ /min 0.262   0.303 0.349 0.245 λ₂ mL/kg 0.024   0.0320.027 0.028 V₁ μg/mL 447.8 608.5  400.1 452.6 Vss μg/mL 1347.9 1119.0 833.0 921.7 * p < 0.05

TABLE 12 Summary of mean plasmatic pharmacokinetic parameters forDiprivan and PPF-PM formulations PK PPF-PM PPF-PM PPF-PM parametersUnits Diprivan ® 7% w/w 10% w/w 12% w/w C_(max) μg/mL 11.7  6.0 *** 7.66.1 *** C₀ μg/mL 12.4 6.2  6.6 6.8    AUC t μg · min/mL 126.5  77.3 ****  84.2 *** 76.7 **** AUC inf μg · min/mL 132.8  87.2 ***    89.2 ****85.4 ***  CL mL/min/kg 19.2  27.2 *** 21.9  28.3    MRT Min 77.1 122.5***   113.0 **** 130.9 **   T ½ Min 17.5  23.8 **** 19.5  26.1    T ½{acute over (α)} Min 1.4 3.5 * 2.0 3.1    T ½ β Min 16.6 38.7   20.3 32.2 *   λ₁ /min 0.508   0.243 ***  0.432 0.287 * λ₂ mL/kg 0.042   0.024***  0.038   0.024 **** V₁ μg/mL 626.0 1875.0 **** 1052.9 *  1622.0****  Vss μg/mL 1467.5 3293.3 ****  2481.9 *** 3632.1 ****  * p < 0.05** p < 0.03 *** p < 0.02 **** p < 0.01

TABLE 13 Mean partition coefficient (Kp RBC: Plasma) of propofol inblood following a single intravenous dose (target 10 mg/kg) ofDiprivan ® and 3 PPF-PM formulations (7, 10 and 12%) Time Kp Kp PPF-PMKp PPF-PM Kp PPF-PM (min) Diprivan ® 7% w/w 10% w/w 12% w/w 1 8.5 10.414.0 15.7 3 7.6 9.9 12.0 11.3 5 6.4 5.8 9.8 10.5 7.5 5.6 5.9 5.9 7.0 103.7 4.2 4.2 5.7 15 2.1 4.1 3.9 3.2 30 2.2 2.7 2.1 2.5 60 1.1 0.9 0.6 0.775 0.8 0.5 0.5 0.6

Example 11

PVP-PDLLA (POLYMER 1) was dissolved directly in water at concentrationsbetween 140 to 350 mg/mL. Propofol is added to the PVP-PDLLA solutionand mixed until a homogenous solution is obtained. The solution is thendiluted to a concentration of 1% w/v of propofol (7%, 9%, 10% and 12%w/w drug loading levels), The solutions were then filtered using 0.2 μmsterile filters and frozen in ethanol/dry ice bath before beinglyophilized for 48 hours. Solid lyophilized cakes were reconstituted byadding sterile dextrose 5% for injection to yield a propofolconcentration of 1% w/v (10 mg/mL). Micelle size distributions were thenmeasured at 1% w/v and 0.1% w/v propofol concentrations to evaluate theeffect of dilution. At 0.01% w/v (1/100 dilution), the light scatteringsignal was very weak for obvious reasons. The sample at 7% w/w drugloading level was the only one measured at 0.01% w/v-propofolconcentration. All solutions were stable visually and no phaseseparation or precipitation was observed upon dilution. Characteristicsof these formulations are presented in the table below.

TABLE 14 Characteristics and, particle size and stability, of propofolpolymeric micelle formulations upon dilution Sample ID DLL Micelle Size(nm) POLYMER (%) Dilution 1% w/v 0.1% 0.01% 1 w/w medium PPF w/v w/vFR041124 7 Dextrose 5% 23 23 18 (99.4%) (99.4%) (100%) DLG041123 9Dextrose 5% 24 24 ND (99.6%) (99.9%) DLG041123 10 Dextrose 5% 24 25 ND(99.5%) (99.6%) DLG041123 12 Dextrose 5% 26 30 ND (97%) (98.6%)

Example 12

Microbial growth study. Formulations prepared as per example 2 werereconstituted in three different media (water for injection, dextrose 5%w/v and saline 0.9% w/v) inoculated with 4 different strains ofbacteria. Furthermore, reconstitution media alone (saline, dextrose 5%and water for injection) and polymer solutions without any propofol inall three different reconstitution media were also inoculated forcomparison, 1×10⁴ cfu/mL were added to each articles tested (solutions,formulations, media). Dirpivan® emulsion was also inoculated forcomparison. Characteristics of polymer solutions and formulations follow(table) and graphical results on microbial proliferation in differenttests are presented below.

TABLE 15 Characteristics of formulation and polymer solutions tested formicrobial growth study. Formulation Propofol Reconstitution POLYMER DLLConc. 1 (%) w/w Medium Time Clarity (mg/mL) PVP-PLA 0 WFI <30 Clear 0sec PVP-PLA 0 Dextrose <30 Clear 0 sec PVP-PLA 0 0.9% Saline <30 Clear 0w/v sec PPF-PM 10 WFI <30 Clear 9.56 sec PPF-PM 10 Dextrose <30 Clear9.72 sec PPF-PM 10 0.9% Saline <30 Clear 9.89 w/v sec

Results of the microbial growth study indicate that the PVP-PLAsolutions of the invention (containing no propofol) are most of the timenot significantly different than proliferation observed in thereconstitution media (water for injection, saline 0.9% w/v and dextrose5% w/v) alone. The addition of propofol to form the propofol polymericmicelle (PPF-PM) formulations demonstrates that the intrinsicbactericidal property of propofol is active in killing all bacteriainoculated, independent on the reconstitution media or the polymer.Diprivan as shown highest microbial growth support in all cases.

FIGS. 7-18: Microbial growth time profile of polymer solutions(PVP-PLA), propofol polymeric micelle formulations (PPF-PM), Diprivan®and reconstitution media of all 4 strains of bacteria tested.

Example 12

PVP-PDLLA (POLYMER 4) is dissolved directly in 100 mM sodium phosphatebuffer, pH 7.4. Propofol is added to the solution and mixed. Once theclear solution is obtained, the solution is diluted to 1% w/v propofolconcentration and a final buffer concentration of 75 mM. The solutionswere then lyophilized. The freeze dried cakes were then reconstituteddirectly with 2%, 1% and 0.2% w/v lidocaine solutions. Particle size andpH of solutions were measured daily over a period of 5 days. Results arepresented below.

TABLE 16 Propofol polymeric micelle stability in solution with differentlidocaine concentration Propofol 1% Particle size (nm)/pH Lidocaine Atconcentration reconstitution Day 1 Day 2 Day 3 Day 4 0.2% (2 mg/mL)  35.1/6.35 35.8/6.4  36.8/6.20 39.2/6.36 39.9/6.26 1% (10 mg/mL)33.9/6.53 34.5/6.38 33.0/6.39 37.5/6.49 37.0/6.43 2% (20 mg/mL)31.9/6.87 34.5/6.56 33.2/6.60 32.4/6.71 31.1$6.65

Example 13

Two other liquid biologically active agents have also been successfullyloaded in PVP-PLA micelles using the same procedure. 2-phenoxyethanol(50 mg/mL) and quinaldine (10 mg/mL) were added to aqueous PVP-PLAsolutions (90 mg/mL) containing 75 mM (final concentration) of sodiumphosphate buffer (pH 7.4). The clear solutions were then diluted tosuitable concentration for UV absorbance measurements prior to freezingand lyophilization. The resulting lyophilizate was then reconstituted byaddition of water to approximately the same concentration, i.e. 50 mg/mLfor 2-phenoxyethanol and 10 mg/mL for quinaldine. Clear solutions wereobtained. UV absorbance was then measured to assess the presence of thetwo drugs. Results below indicate that the two biologically activeliquids were retained in the PVP-PLA, micelles.

TABLE 17 Formulation 1: 2- Phenoxyethanol (final concentration of drug =50 mg/mL) Formulation 1 Abs (228 nm) Before freeze drying 0.76040 Afterreconstitution 0.62017Formulation 1. was diluted with USP water to a 0.5 mg/mL concentrationfor UV measurement

TABLE 18 Formulation 2: Quinaldine (final concentration of drug = 10/mL)Formulation 2 Abs (225 nm) Before freeze drying 2.08290 Afterreconstitution 1.72110Formulation 2 was diluted with USP water to a 0.1 mg/mL concentrationfor UV measurement.

It is to be understood that while a certain form of the invention isillustrated, it is not to be limited to the specific form or arrangementherein described and shown. It will be apparent to those skilled in theart that various changes may be made without departing from the scope ofthe invention and the invention is not to be considered limited to whatis shown and described in the specification and drawings/figures.

One skilled in the art will readily appreciate that the presentinvention is well adapted to carry out the objectives and obtain theends and advantages mentioned, as well as those inherent therein. Theembodiments, methods, procedures and techniques described herein arepresently representative of the preferred embodiments, are intended tobe exemplary and are not intended as limitations on the scope. Changestherein and other uses will occur to those skilled in the art which areencompassed within the spirit of the invention and are defined by thescope of the appended claims.

Although the invention has been described in connection with specificpreferred embodiments, it should be understood that the invention asclaimed should not be unduly limited to such specific embodiments.Indeed, various modifications of the described modes for carrying outthe invention which are obvious to those skilled in the art are intendedto be within the scope of the following claims.

What is claimed is:
 1. A solid product suitable for reconstitution to anessentially clear, stable solution upon addition of an aqueousreconstituting solvent thereto, said solid product comprising anintimate mixture of at least one stabilizing agent, and at least oneliquid biologically active agent loaded within said stabilizing agent,in such a manner that said liquid biologically active agent isintimately associated with said stabilizing agent in a substantiallysolid product; whereby upon hydration with a reconstituting aqueoussolvent or solution, said solid product forms said essentially clearstable solution in which said at least one biologically active agent ispresent as stable nanodispersions or micelles loaded with said at leastone biologically active agent.
 2. A solid product according to claim 1,which comprises about 0.1% to about 25% w/w of said biologically activeagent.
 3. A solid product according to claim 2, which comprises about 1%to about 12% w/w of said biologically active agent.
 4. A solid productaccording to claim 1, wherein said liquid biologically active agent isinsoluble in water.
 5. A solid product according to claim 1 wherein saidliquid biologically active agent is adapted for use as an intravenousinjection.
 6. A solid product according to claim 1 wherein said liquidbiologically active agent is an anaesthetic agent.
 7. A solid productaccording to claim 1 wherein said liquid biologically active agent isselected from the group consisting of propofol, 2-phenoxyethanol,quinaldine, methoxyflurane, and combinations thereof.
 8. A solid productaccording to claim 6 wherein said anaesthetic agent is propofol.
 9. Asolid product according to claim 1 which is obtained by lyophilizing orspray-drying a mixture of said at least one stabilizing agent, said atleast one liquid biologically active agent and at least one solventtherefore.
 10. A solid product according to claim 1 wherein saidstabilizing agent is selected from the group consisting of dispersingagents and surfactants.
 11. A solid product according to claim 1 whereinsaid stabilizing agent comprises a dispersing agent.
 12. A solid productaccording to claim 11 wherein said dispersing agent is an amphiphiliccopolymer.
 13. A solid product according to claim 12 wherein saidamphiphilic polymer is a linear, branched or star-shaped block polymer.14. A solid product according to claim 12 wherein said amphiphilicpolymer includes a hydrophilic part that comprises at least one memberselected from the group consisting of poly(ethylene oxide),poly(N-vinylpyrrolidone), poly(N-2-hydroxypropylmethacrylamide),poly(2-ethyl-2-oxazoline), poly(glycidol),poly(2-hydroxyethylmethacrylate), poly(vinylalcohol), polymethacrylicacid derivatives, poly(vinylpyridinium),poly((ammoniumalkyl)methacrylate), poly((aminoalkyl)methacrylate) andcombinations and derivatives thereof; and a hydrophobic segment selectedfrom the group comprising a poly(ester), poly(ortho ester), poly(amide),poly(ersteramide) poly(anhydride), poly(prophylene oxide),poly(tetrahydrofuran) and combinations thereof.
 15. A solid productaccording to claim 14 wherein said hydrophobic segment comprises apoly(ester) selected from the group consisting of poly(e-caprolactone),poly(lactide), poly(glycolide), poly(lactide-co-glycolide),poly(hydroxyl-alkanoates), poly(β-malic acid), and derivatives thereof.16. A solid product according to claim 12 wherein said amphiphiliccopolymer consists of PVP-PDLLA.
 17. A solid product according to claim1 wherein said stabilizing agent comprises a surfactant.
 18. A solidproduct according to claim 17 wherein said surfactant is selected fromthe group comprising lauryl sulphate, hexadecyl pyridinium chloride,polysorbates, sorbitans, poly(oxyethylene) alkyl ethers,poly(oxyethylene alkyl esters and combinations thereof.
 19. A solidproduct according to claim 9 wherein said solvent is selected from thegroup consisting of water, t-butanol, n-butanol, dioxane, pyridine,pyrimidine, piperidine, sodium phosphate buffer pH 7.4 and mixturesthereof.
 20. A solid product according to claim 19 wherein said solventcomprises water.
 21. A process for the production of a solid productsuitable for reconstitution to a clear stable solution upon addition ofan aqueous solution thereto, which comprises forming a first mixturecomprising a solution of at least one stabilizing agent and at least onesolvent, under conditions to achieve micelle or nanodispersionformation; adding at least one liquid biologically active agent to saidfirst mixture in such a manner to load said micelle or nanodispersiontherewith and form a second mixture; treating said second mixture underconditions effective to remove said solvent therefrom while forming asubstantially solid product that contains said liquid biologicallyactive agent intimately associated with said stabilizing agent, saidsolid product upon hydration being capable of forming a clear stablesolution in which said at least one biologically active agent is presentas nanodispersion or micelle loaded with said at least one biologicallyactive agent.
 22. A process for the production of a stabilizednanodispersion or loaded micelle containing a liquid biologically activeagent which comprises hydrating a solid product as defined in claim 1,under conditions to provide said stabilized nanodispersions or loadedmicelle.
 23. Process according to claim 21 which comprises adding atleast one additive to said first and/or second mixture.
 24. The processaccording to claim 21 which comprises filtering said solution to yield asterile filtrate.
 25. The process according to claim 21 wherein saidsolvent is selected from the group consisting of water, t-butanol,n-butanol, dioxane, pyridine, pyrimidine, piperidine, sodium phosphatebuffer pH 7.4 and combinations thereof.
 26. The process according toclaim 25 wherein said solvent consists of water.
 27. The process inaccordance with claim 22 wherein said step of hydrating includescombining said solid product with a sufficient amount of water, salinesolution or dextrose solution.
 28. The process in accordance with claim23 wherein said additive is at least one member selected from the groupconsisting of a buffer, a cryoprotectant, an analgesic, a lyoprotectant,a bulk forming agent, e.g. polyvinylpyrrolidone, lidocaine,poly(ethylene glycol), lactose, trehalose, mannitol, saccharides, aminoacids soluble in said solvent, or combinations thereof.
 29. The processin accordance with claim 21 wherein said forming step further includesat least one dissolution enhancing means selected from the groupconsisting of sonicating, vortexing and heating.
 30. The process inaccordance with claim 21 wherein said stabilizing agent is at least onemember selected from the group consisting of a polymer, a copolymer, asmall molecular weight surfactant, and combinations thereof.
 31. Theprocess according to claim 21 wherein said liquid biologically activeagent is water insoluble.
 32. The process according to claim 21 whereinsaid water insoluble liquid biologically active agent is selected fromthe group consisting of propofol, 2-phenoxyethanol, quinaldine, andmethoxyflurane, and combinations thereof.
 33. The process according toclaim 21 which comprises adding between about 0.1% to about 15% w/v ofsaid liquid biologically active agent to said first mixture.
 34. Theprocess according to claim 33 which comprises adding between about 1%and about 10% w/v of said liquid biologically active agent to said firstmixture.
 35. The process according to claim 32 wherein said liquidbiologically active agent comprises propofol.
 36. A clear liquidconsisting of a stable nanodispersion or micelle comprising a hydratingsolvent and a solid product as defined in claim
 1. 37. A method ofmedical treatment which comprises administering to a patient a clearliquid as defined in claim
 36. 38. A device for producing solidformulations of liquid biologically active agents comprising acontainer, means for adding at least one stabilizing agent and at leastone solvent into said container, mixing means operable with saidcontainer to form a first mixture of said stabilizing agent and saidsolvent under conditions to achieve micelle or nanodispersion therein,means for subsequently adding a liquid biologically active agent to saidfirst mixture and to form a second mixture, means operating said mixingmeans under conditions to treat said second mixture to load said micelleor nanodispersion with said biologically active agent, and means fortreating said loaded micelle or nanodispersion to form a solid productcontaining said liquid biologically active agent intimately associatedwith said stabilizing agent and substantially free of said solvent.